This application is related to co-pending U.S. patent applications entitled Methods of Soft Palate Reduction By Thermal Ablation Using High Intensity Focused Ultrasound, Methods of Tonsil Reduction By Thermal Ablation Using High Intensity Focused Ultrasound, Methods of Turbinate Or Other Soft Tissue Reduction By Thermal Ablation Using High Intensity Focused Ultrasound, Methods of Skin Rejuvenation By Thermal Stimulation Using High Intensity Focused Ultrasound, Focused Ultrasound Ablation Devices Having Malleable Handle Shafts and Methods of Using the Same, and Focused Ultrasound Ablation Devices Having Selectively Actuatable Ultrasound Emitting Elements and Methods of Using the Same, the disclosures of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates generally to the treatment of anatomical tissue of the head and/or neck with high intensity focused ultrasound energy and, more particularly, to reduction of the tongue by thermal ablation using high intensity focused ultrasound.
2. Brief Description of the Related Art
When high intensity ultrasound energy is applied to anatomical tissue, significant physiological effects may be produced in the anatomical tissue resulting from thermal and/or mechanical changes or effects in the tissue. Thermal effects include heating of the anatomical tissue; and, when the tissue is heated to a sufficiently high temperature, tissue damage such as coagulative necrosis is produced. In order to produce thermal effects in anatomical tissue, ultrasound emitting members such as transducers have been used to emit ultrasound energy which is applied to anatomical tissue by positioning the ultrasound emitting members adjacent or in contact with the tissue or by coupling the ultrasound emitting members to the tissue via an acoustic coupling medium. By focusing the ultrasound energy at one or more specific focusing zones within the tissue, thermal effects can be confined to a defined location, region, volume or area, and such location, region, volume or area can be remote from the ultrasound emitting member.
With the use of high intensity focused ultrasound (HIFU) one or more focusing zones at or within a designated target location, region, volume or area within a larger mass, body or area of anatomical tissue can be subjected to high intensity ultrasound energy while tissue surrounding the target area is subjected to much lower intensity ultrasound energy. In this manner, tissue at the target area can be heated to a sufficiently high temperature so as to cause a desired thermal effect such as tissue damage, ablation, coagulation, denaturation, destruction or necrosis while tissue surrounding the target area is not heated to damaging temperatures and, therefore, is preserved. Heating of tissue at a target location, volume, region or area to an ablative temperature creates an ablative lesion in the tissue at the target location, volume, region or area that is desirable in the treatment of various medical conditions, disorders or diseases. For example, the lesion may remain as tissue having altered characteristics or may be naturally degraded and absorbed by the patient""s body and thusly eliminated such that the remaining body, mass or area of tissue is of smaller volume or size due to the absence of the ablated tissue.
The use of high intensity focused ultrasound to eliminate tissue or to alter the characteristics of tissue at a target location, volume, region or area within a larger mass, body or area of anatomical tissue presents many advantages including minimization of trauma and pain for the patient, elimination of the need for a surgical incision, stitches and exposure of internal tissue, avoidance of damage to tissue other than that which is to be treated, altered or removed, lack of a harmful cumulative effect from the ultrasound energy on the surrounding non-target tissue, reduction in treatment costs, elimination of the need in many cases for general anesthesia, reduction of the risk of infection and other complications, avoidance of blood loss, and the ability for high intensity focused ultrasound procedures to be performed in non-hospital sites and/or on an out-patient basis.
Various devices and/or methods for treating anatomical tissue with ultrasound have been proposed as represented by U.S. Pat. No. Re. 33,590 to Dory, U.S. Pat. No. 3,990,452 to Murry et al, U.S. Pat. No. 4,658,828 to Dory, U.S. Pat. No. 4,807,633 to Fry, U.S. Pat. No. 4,858,613 to Fry et al, U.S. Pat. No. 4,951,653 to Fry et al, U.S. Pat. No. 4,955,365 to Fry et al, U.S. Pat. No. 5,033,456 to Pell et al, U.S. Pat. No. 5,036,855 to Fry et al, U.S. Pat. No. 5,054,470 to Fry et al, U.S. Pat. No. 5,065,761 to Pell, U.S. Pat. No. 5,080,101 to Dory, U.S. Pat. No. 5,080,102 to Dory, U.S. Pat. No. 5,117,832 to Sanghvi et al, U.S. Pat. No. 5,134,988 to Pell et al, U.S. Pat. No. 5,143,074 to Dory, U.S. Pat. No. 5,150,711 to Dory, U.S. Pat. No. 5,150,712 to Dory, U.S. Pat. No. 5,158,070 to Dory, U.S. Pat. No. 5,222,501 to Ideker et al, U.S. Pat. No. 5,267,954 to Nita, U.S. Pat. No. 5,269,291 to Carter, U.S. Pat. No. 5,269,297 to Weng et al, U.S. Pat. No. 5,295,484 to Marcus et al, U.S. Pat. No. 5,304,115 to Pflueger et al, U.S. Pat. No. 5,312,328 to Nita et al, U.S. Pat. No. 5,318,014 to Carter, U.S. Pat. No. 5,342,292 to Nita et al, U.S. Pat. No. 5,354,258 to Dory, U.S. Pat. No. 5,380,274 to Nita, U.S. Pat. No. 5,391,197 to Burdette et al, U.S. Pat. No. 5,397,301 to Pflueger et al, U.S. Pat. No. 5,409,002 to Pell, U.S. Pat. No. 5,417,672 to Nita et al, U.S. Pat. No. 5,431,621 to Dory, U.S. Pat. No. 5,431,663 to Carter, U.S. Pat. No. 5,447,509 to Mills et al, U.S. Pat. No. 5,474,530 to Passafaro et al, U.S. Pat. No. 5,492,126 to Hennige et al, U.S. Pat. No. 5,501,655 to Rolt et al, U.S. Pat. No. 5,520,188 to Hennige et al, U.S. Pat. No. 5,542,917 to Nita et al, U.S. Pat. No. 5,620,479 to Diederich, U.S. Pat. No. 5,676,692 to Sanghvi et al, U.S. Pat. No. 5,728,094 to Edwards, U.S. Pat. No. 5,730,719 to Edwards, U.S. Pat. No. 5,733,315 to Burdette et al, U.S. Pat. No. 5,735,280 to Sherman et al, U.S. Pat. No. 5,738,114 to Edwards, U.S. Pat. No. 5,746,224 to Edwards, U.S. Pat. No. 5,762,066 to Law et al, U.S. Pat. No. 5,800,379 to Edwards, U.S. Pat. No. 5,800,429 to Edwards, U.S. Pat. No. 5,800,482 to Pomeranz et al, U.S. Pat. No. 5,807,308 to Edwards, U.S. Pat. No. 5,817,049 to Edwards, U.S. Pat. No. 5,823,197 to Edwards, U.S. Pat. No. 5,827,277 to Edwards, U.S. Pat. No. 5,843,077 to Edwards, U.S. Pat. No. 5,871,524 to Knowlton, U.S. Pat. No. 5,873,845 to Cline et al, U.S. Pat. No. 5,873,902 to Sanghvi et al, U.S. Pat. No. 5,879,349 to Edwards, U.S. Pat. No. 5,882,302 to Driscoll, Jr. et al, U.S. Pat. No. 5,895,356 to Andrus et al, U.S. Pat. No. 5,928,169 to Schxc3xa4tzle et al and U.S. Pat. No. 5,938,608 to Bieger et al.
In particular, the use of high intensity focused ultrasound to thermally damage, ablate, coagulate, denature, cauterize, necrotize or destroy a target volume of tissue is exemplified by U.S. Pat. No. Re. 33,590 to Dory, U.S. Pat. No. 4,658,828 to Dory, U.S. Pat. No. 4,807,633 to Fry, U.S. Pat. No. 4,858,613 to Fry et al, U.S. Pat. No. 4,951,653 to Fry et al, U.S. Pat. No. 4,955,365 to Fry et al, U.S. Pat. No. 5,036,855 to Fry et al, U.S. Pat. No. 5,054,470 to Fry et al, U.S. Pat. No. 5,080,101 to Dory, U.S. Pat. No. 5,080,102 to Dory, U.S. Pat. No. 5,117,832 to Sanghvi et al, U.S. Pat. No. 5,143,074 to Dory, U.S. Pat. No. 5,150,711 to Dory, U.S. Pat. No. 5,150,712 to Dory, U.S. Pat. No. 5,295,484 to Marcus et al, U.S. Pat. No. 5,354,258 to Dory, U.S. Pat. No. 5,391,197 to Burdefte et al, U.S. Pat. No. 5,431,621 to Dory, U.S. Pat. No. 5,492,126 to Hennige et al, U.S. Pat. No. 5,501,655 to Rolt et al, U.S. Pat. No. 5,520,188 to Hennige et al, U.S. Pat. No. 5,676,692 to Sanghvi et al, U.S. Pat. No. 5,733,315 to Burdette et al, U.S. Pat. No. 5,762,066 to Law et al, U.S. Pat. No. 5,871,524 to Knowlton, U.S. Pat. No. 5,873,845 to Cline et al, U.S. Pat. No. 5,873,902 to Sanghvi et al, U.S. Pat. No. 5,882,302 to Driscoll, Jr. et al, U.S. Pat. No. 5,895,356 to Andrus et al, U.S. Pat. No. 5,928,169 to Schxc3xa4tzle et al and U.S. Pat. No. 5,938,608 to Bieger et al.
Ablation of anatomical tissue of the head and/or neck in order to treat various airway related disorders or conditions, such as airway obstructions, snoring disorders and sleep apnea syndrome, has been proposed as illustrated by U.S. Pat. No. 5,423,812 to Ellman et al, U.S. Pat. Nos. 5,456,662, 5,514,131, 5,624,439, 5,674,191, 5,707,349, 5,718,702, 5,728,094, 5,730,719, 5,738,114, 5,743,870, 5,743,904, 5,746,224, 5,800,379, 5,800,429, 5,807,308, 5,817,049, 5,823,197, 5,827,277, 5,843,077 and 5,879,349 to Edwards and WO 97/43970. The latter patents disclose ablation of various structures of the anatomical airway to alleviate or eliminate snoring disorders and/or obstructive sleep apnea syndrome in patients. U.S. Pat. No. 5,423,812 relates to electrosurgical stripping of tissue. U.S. Pat. Nos. 5,456,662, 5,514,131, 5,624,439, 5,674,191, 5,707,349, 5,718,702, 5,728,094, 5,730,719, 5,738,114, 5,743,870, 5,743,904, 5,746,224, 5,800,379, 5,800,429, 5,807,308, 5,817,049, 5,823,197, 5,827,277, 5,843,077, 5,879,349 and WO97/43970 disclose RF ablation using tissue penetrating electrodes. U.S. Pat. Nos. 5,707,349, 5,728,094, 5,730,719, 5,738,114, 5,746,224, 5,800,379, 5,800,429, 5,807,308, 5,817,049, 5,823,197, 5,827,277, 5,843,077 and 5,879,349 refer to ultrasound as a possible source of ablative energy.
Depending on the thickness, size and/or shape of the tongue in relation to other tissues or anatomical structures of the airway, the tongue may present an airway restriction or obstruction and/or source of resonance or vibration causing or contributing to snoring disorders and/or obstructive sleep apnea syndrome. For example, one type of snoring disorder results from obstruction of the oropharyngeal isthmus by other tissue or structures of the airway. When the oropharyngeal isthmus or another portion of the airway is/are obstructed or restricted, such as by the tongue or other tissues and/or anatomical structures of the airway, an interruption in or cessation of breathing may occur resulting in obstructive sleep apnea syndrome. Sleep apnea syndrome is a medical condition characterized by episodes of apnea during sleep causing daytime hypersomnomulence, morning arm aches, intellectual deterioration, cardiac arrythmias, snoring and/or thrashing during sleep.
Treatments for snoring disorders and/or sleep apnea syndrome have included various pharmacological, surgical and physical measures to reduce or eliminate tissue vibrations and/or airway obstructions or restrictions so as to enhance the flow of air through the patient""s airway. Pharmacological measures have included the use of medications such as protriptyline, medroxyprogesterone, acetazolamide, theophylline, nicotine and other medications in addition to avoidance of central nervous system depressants such as sedatives or alcohol. Such medications typically have undesirable side effects and are of limited effectiveness. Surgical measures have included uvulopalatal pharyngoplasty, tonsillectomy, surgery to correct severe retrognathia and tracheostomy. Another surgical measure has involved pulling the tongue anteriorly and suspending it by sutures to deter it from falling back in the oral cavity during sleep and vibrating or causing an occlusion in the airway. Other surgical measures have included removing a portion or portions of the tongue and/or other anatomical tissue or structures which can obstruct or restrict the patient""s airway.
Surgical techniques have been proposed using standard surgical instruments, laser energy and RF energy. Although surgical measures are generally more effective than medications, the risks associated with surgery can be prohibitive and/or are often unacceptable to the patient. In addition, conventional surgery is associated with considerable trauma and pain for the patient as well as the potential for post-operative complications. Laser and RF energy ablation procedures are less invasive than surgery with instruments but are difficult to control; and, if too much tissue is ablated, severe consequences may ensue. Multiple ablation treatments are usually required in order to achieve the results desired, and each treatment may cause the patient to experience significant pain for a considerable length of time. Laser and RF energy ablation systems are not able to repeatedly and consistently produce a discrete lesion of definitive size. Physical measures to treat snoring disorders and/or sleep apnea syndrome include weight loss and the use of various appliances.
Ablation of the tongue to treat snoring disorders and/or obstructive sleep apnea syndrome is exemplified by U.S. Pat. Nos. 5,624,439, 5,707,349, 5,728,094, 5,730,719, 5,738,114, 5,743,904, 5,800,379, 5,807,308, 5,817,049 and 5,879,349 to Edwards. As noted above, U.S. Pat. Nos. 5,707,349, 5,728,094, 5,730,719, 5,800,379, 5,807,308, 5,817,049 and 5,879,349 disclose the use of RF electrodes to transmit electromagnetic energy to tissue to be ablated while merely alluding to ultrasound as a possible source of ablative energy. The electrodes are introduced within the tissue to effect ablation in the interior of the tissue.
Accordingly, the need exists for methods of tongue reduction by thermal ablation using high intensity focused ultrasound whereby the tongue of a patient can be reduced in volume, bulk or size, via elimination and/or alteration of the normal tissue, to reduce or eliminate vibration of the tongue and/or to increase the space or size of the patient""s airway in a minimally invasive, bloodless procedure not requiring physical penetration of the tongue and while confining ablation to a specific target area or areas within the tongue.
Accordingly, it is a primary object of the present invention to overcome the various disadvantages of prior methods of tongue reduction.
It is also an object of the present invention to effect tongue reduction by thermal ablation using high intensity focused ultrasound.
Another object of the present invention is to utilize high intensity focused ultrasound to treat airway obstructions.
A further object of the present invention is to utilize high intensity focused ultrasound to treat snoring disorders.
An additional object of the present invention is to utilize high intensity focused ultrasound to treat obstructive sleep apnea syndrome.
It is also an object of the present invention to use high intensity focused ultrasound to thermally ablate the tongue without impairing tongue function.
Yet another object of the present invention is to use high intensity focused ultrasound to produce a lesion within tissue of the tongue while preserving the mucosa of the tongue.
The present invention has as a further object to use high intensity focused ultrasound to form a subsurface lesion in the tongue including relatively stiffer tissue to inhibit tongue vibration.
The present invention also has as an object to use high intensity focused ultrasound to ablate the tongue at an internal target area without physical penetration of the tongue by the member used to deliver the ultrasound energy.
Still a further object of the present invention is to focus ultrasound energy within the tongue to form an internal lesion beginning a predetermined distance beneath an external surface of the tongue.
The present invention also has as an object to focus ultrasound energy, emitted by an ultrasound emitting member, within the tongue to ablate tissue of the tongue at a target area beginning a predetermined distance from an active face of the ultrasound emitting member.
Some of the advantages of the present invention are that varying intensity levels of ultrasound energy can be delivered to tissue of the tongue for varying periods of time, the duration or time of high intensity focused ultrasound delivery or application to the tissue needed to accomplish a desired ablation may be relatively brief depending on desired lesion size and/or desired effect on the tissue, the transducer or other member used to emit the ultrasound energy may remain stationary or may be moved manually or automatically from one position or location to another on the tongue in order to ablate a target area, a plurality of individual target areas can be ablated with the positions or locations for the target areas selected such that the target areas, when ablated, cumulatively form a single lesion of desired size and/or shape, the transducer or other member can include a single transducer element or a plurality of transducer elements, the ultrasound emitting member can remain stationary while a transducer element or elements thereof is/are moved to scan a target area with focused ultrasound, the transducer or other member may be designed with a focusing configuration designed to ensure that the lesion begins a desired depth within the tissue and that the lesion has a desired depth, anatomical tissue of the tongue may be effectively removed to debulk or reduce the size, volume and/or configuration of the tongue, tissue of the tongue may be rigidified or stiffened via thermal damage thereto to reduce the volume of relatively softer, normal tongue tissue, tongue reduction is accomplished with minimal trauma and pain for the patient, the transducer or other member is positioned externally adjacent or in contact with an external surface of the tongue or is acoustically coupled with tissue of the tongue to form an internal lesion without damaging the external tissue surface and without formation of fistulas, no external wound is presented since the mucosa of the tongue is preserved, and a discrete lesion of definitive size can be repeatedly and consistently produced.
These and other objects, advantages and benefits are realized with the present invention as generally characterized in a method of tongue reduction by thermal ablation using high intensity focused ultrasound wherein an ultrasound emitting member is introduced in a patient""s oral cavity and is positioned adjacent an external tissue surface of the tongue. Ultrasound energy is emitted from the ultrasound emitting member into the tissue of the tongue, and the ultrasound energy is focused within the tongue at one or more focusing zones at or within a target area disposed beneath the external tissue surface. Due to focusing of the ultrasound energy, the ultrasound energy is of higher or greater intensity in tissue at the one or more focusing zones than in tissue surrounding the target area. The high intensity ultrasound energy at the one or more focusing zones causes the tissue at the target area to be heated to an ablative temperature to create an internal lesion. Once a desired lesion or lesions has/have been formed in the tongue, the ultrasound emitting member is withdrawn from the patient""s oral cavity. Depending on the characteristics of the lesion, all or some of the lesion may be degraded and absorbed by the patient""s body such that the tongue is smaller in size than prior to treatment. Depending on the characteristics of the lesion, all or some of the lesion may remain as altered tissue, such as scar tissue that is stiffer, tighter or more rigid than the normal undamaged tongue tissue, the volume of normal undamaged tissue therefore being less than prior to treatment. Since the tongue is smaller in size and/or more stiff, the patient""s airway is correspondingly larger in size and/or the tongue is less likely to vibrate so as to eliminate or alleviate various airway related disorders or conditions including airway obstructions, snoring disorders and sleep apnea syndrome.
The ultrasound emitting member has a focusing configuration causing the ultrasound energy to be focused a predetermined distance from an active face of the ultrasound emitting member and, therefore, from the external tissue surface, so that the mucosa of the tongue is preserved. Also, the focusing configuration results in formation of a lesion of predetermined or known depth, which is selected so that the lesion does not extend deeper than desired in the tissue. The location and arrangement of the one or more focusing zones in the tissue results in formation of a specific size lesion having a specific configuration. A single discrete lesion or a plurality of single discrete lesions can be formed in the tongue in a single procedure or treatment performed at one time or in multiple procedures or treatments performed at different times. Where a plurality of lesions are formed, the lesions can comprise lesion portions formed contiguous to one another so that the lesion portions together form or create a single lesion of larger size and/or of a desired configuration.